Apparatus for scraping liquid off of sheet material

ABSTRACT

An apparatus for scraping liquid off of sheet material, for example, in photo developing, comprises a combination of a pair of drive rollers having a flange or belt provided for feeding the sheet material by gripping both edges while not contacting the image portion with the rollers. Air supply boxes are provided at the outlet side of the pair of rollers co-operating with the rollers to jet air onto the surface of the sheet material thereby blowing out any excess of the liquid.

United States Patent [191 Sato et al.

[111 3,779,206 [4 1 Dec. 18, 1973 APPARATUS FOR SCRAPING LIQUID OFF OF SHEET MATERIAL Inventors: Ma samichi Sato; Isoji Takahashi, both of Asaka, Japan Assignee: Fuji Photo Film Company, Ltd.,

Nakanuma, Japan Filed: Jan. 20, 1972 Appl. No.: 219,540

[30] Foreign Application Priority Data Jan. 20, 1971 Japan 46/1494 U.S. Cl 118/63, 118/104, 118/117, 118/D1G. 23, 95/89 A, 355/15 Int. Cl. B05c 11/06 Field of Search 118/63, DIG. 23, 118/103,106,114-1l8;95/89 A; 355/15 References Cited UNlTED STATES PATENTS 6/1949 Kunz 118/63 1/1951 Keller 118/63 UX Primary Examiner-James Kee Chi Alt0rneyRichard C. Sughrue et al.

[57] ABSTRACT An apparatus for scraping liquid off of sheet material,

for example, in photo developing, comprises a combination of a pair of drive rollers having a flange or belt provided for feeding the sheet material by gripping both edges while not contacting the image portion with the rollers. Air supply boxes are provided at the outlet side of the pair of rollers co-operating with the rollers to jet air onto the surface of the sheet material thereby blowing out any excess of the liquid.

5 Claims, 4 Drawing Figures MEANS l3 APPARATUS FOR SCRAPING LIQUID OFF OF SHEET MATERIAL BACKGROUND OF THE INVENTION I. Field of the Invention This invention relates to an apparatus for scraping liquid off of sheet material, for example, such as film, photographic printing paper, and sensitive paper moistened with liquid.

2. Description of the Prior Art In a photographic processing device, electrophotographic liquid developing apparatus or any other apparatus for processing sheet material using liquid, liquid must be scraped off in order to remove excessive processing liquid used in the previous treatment step when it is transferred from one processing step to another.

There has been known an apparatus for scraping liquid off of moistened sheet material by passing the sheet material between two parallel squeeze rollers rotating in opposite directions to each other to roll the material so as to scrape the liquid from the surface of the sheet material relatively opposite to the feeding direction of the material.

Since squeeze rollers, however contact directly with the surface of the sheet material to be scraped off and the surface of the material is fragile, the surface tends to be damaged or destroyed, and often the rear end of the sheet material retains the liquid.

, SUMMARY OF THE INVENTION An object of the present invention is, therefore, to provide a novel and improved apparatus for effectively scraping liquid off of sheet material, and especially photographic material.

Another object of the invention is to provide an apparatus for scraping liquid off the sheet material which does not directly contact the surface of the material at the image portion and yet sufficiently removes the liquid.

A further object of the invention is to provide animproved apparatus for scraping liquid off of the sheet material which is adapted for scraping liquid off an electrophotographic material, silver halide photographic light-sensitive material or any other sheet material moistened with non-polar liquid.

In order to accomplish these objects, the present invention provides an air jet located at the rollers with a flange or belt support for floating the sheet material at the image portion in non-contact with the rollers and thereby effectively removing the liquid.

The term liquid scraping used in this disclosure does not mean to completely scrape off the liquid adhered onto the surface of the sheet material. It means, as used, to remove excessive liquid adhered onto the surface of the moistened sheet material in such a manner that only a thin controlled layer is retained. The

thickness of the retained liquid film is in the range of 0.5 10 microns.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects of this invention, as well as other ad- DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a basic structure of one embodiment of an apparatus for scraping off liquid in accordance with this invention. A pair of rollers including a roller 10 having flanges 11 at both ends for contacting with both right and left edges of sheet material 18 and a roller 12 having flanges 13 similar to the roller 10 are and the flanges 11 supported by a side plateand are rotated in the direction of arrows 14 and 15 respectively by a suitable driving means. Air supply boxes 16 and 17 fixed to the side plate are provided above the roller 10 and below the roller 12. Moistened sheet material 18 to be scraped (hereinafter called simply sheet) is inserted between the pair of rollers 10 and 12 in such a manner that both edges of the sheet 18 are interleaved between the 11 and 13, and the sheet 18 is fed in the direction of arrow 19. The lower end portion of the front wall 20 of the air box 16 is so bent as to cover the roller 10. It is desirable that the gap between the roller 10 and the front wall 20 be as small as possible. The gap between the lip 20a of the front wall 20 and the sheet material 18 is preferably 0.1-2 mm. The rear wall 21 almost contacts at the lip 21a thereof with the roller 10 but does not prevent its rotation. The lower end of both side walls of the air supply box-16 are closely fitted with the roller 10 or the flange 11 but do not prevent its rotation. The air supply box 17 is constructed in the same shape as the air box 16 and is disposed adjacent the roller 12.

Air is supplied into the interiors of the air supply boxes 16 and 17 by a fan (not shown) in such a manner that the air is blown onto the sheet 18 through the gaps between the front wall 2.0 and the roller 10, and between the front wall 22 and the roller 12. Thus, liquid on the surface of the sheet 18 is blown out in the direction opposite to the traveling direction of the sheet 18 so that it is retained at the rear end of the sheet as shown by reference numeral 24 and 25 in the drawing.

' resin, vinyl chloride resin, or polyamide resin, and the vantages and features thereof, will become apparent diameters of the flanges l1 and 13 are enlarged by 0.05 6 mm in comparison with those of the rollers 10 and 12.

Though the aforementioned embodiment is described with respect to both the front and back surface of the sheet moistened with liquid, when the sheet is moistened only on one side, an air supply box can be disposed only on the moistened side.

FIG. 2 shows a side sectional view illustrating another embodiment of the invention. Drive rollers 28 and 29 having flanges 32 and 33 at both ends are supported parallel with the side plate to be rotated by a suitable driving means in the direction designated by an arrow. The rollers 26 and 27 are so provided as to,have grooves with respect to the drive rollers 28 and 29 thereon. Grooves 30 and 31 are formed along the circular periphery of the rollers 26 and 27 in the neighborhood of both ends so that an endless belt 34 may be engaged therewith in such a manner that the endless belt 34 is engaged on the rollers 26 and 27 so as to rotate in the direction designated by an arrow 35. The endless belt 34 is of flexible electroconductive or insulating material and the width and thickness are preferably 1 20mm and 0.1 2 mm respectively. The grooves 30 and 31 are necessary to have the width sufficient that the endless belt 34 projects approximately 0.05 2mm from the surface of the rollers 26 and 27 when the endless belt 34 is engaged therewith.

The sheet 18 is fed between the rollers 27 and 29 and between the rollers 26 and 28 so that both ends of the sheet are interleaved between the endless belt 34 and the flanges 32 and 33 such that the surface of the sheet may travel in the direction of an arrow 19 without contacting with the surface of the rollers. The air supply boxes 161 and 171 are the same in shape as the air supply boxes 16 and 17 shown in FIG. 1.

As described above, the liquid scraping apparatus shown in FIG. 2 uses the rollers with flanges 32 and 33 as driving rollers 28 and 29 and uses the endless belt 34 to pair the rollers, but a good result may be obtained even though the endless belt is engaged with the drive rollers 28 and 29 while the rollers having flanges at both ends are used as a pairing rollers 26 and 27.

FIG. 3 is a side sectional view illustrating a further embodiment of this invention. The sheet 18 to be scraped is fed between a pair of rollers 100 and 120 provided with flanges 110 and 130 at both ends in the direction designated by an arrow 19.

The front wall 200 of the air supply boxes 162 and 172 are fixed so as not to move, but the rear wall 210 is constructed with a plate of 0.05 0.5 mm in thickness made of resilient thin material, such as, for example, phosphorus bronze, brass, polyethylene film, or polyethyleneterephthalate film. The rear wall 210 of the resilient thin plate contacts with rollers 100 and 120 only while the air is discharged. The distance between the rollers at the bottom end of the front wall 200 and the sheet 18 is the same as that shown in FIG. 1.

FIG. 4 shows an apparatus assembled with the liquid scraping apparatus of FIG. 2 in an electrophotographic liquid developing apparatus. The electrophotographic material 180 which has gone through the respective steps of charging and exposing and which is formed with an electrostatic latent image thereon is fed into the developing section 40 so that the latent image surface is up. The developing portion 40 is so constructed as to position the liquid scraping apparatus shown in FIG. 2 in the developing container 41. Liquid developer 42 dispersed with pigment in a high insulating carrier liquid is maintained in the developing container 41, and this liquid developer 42 is supplied from the slit 44 of the developing liquid supply pipe 43 between the electrode rollers 26 and 27 by a pump (not shown) so as to develop the latent image of the electrophotographic material 180. The developed electrophotographic material 180 is scraped off the developing liquid by the air jetted from the air supply boxes 161 and 171 and then fed into the cleaning section 45.-The amount of the jetted air is so adjusted that a thin developing liquid film exists on the surface of the electrophotographic material 180, but the excessive developing liquid is removed. The cleaning portion 45 has metallic or insulating rollers with flanges at both ends consists ofa first pair of rollers 46 a and 46 b, a second pair of rollers 47 a and 47 b, and a third pair of rollers 54 a and 54 b. Air supply boxes 48 and 49 are provided adjacent the rollers and supported on the side plate in the cleaning container 50. Cleaning liquid 51 having a high insulating characteristic and a low boiling point is maintained in the cleaning liquid container 50 so that the cleaning liquid 51 is pumped up into the cleaning liquid supply pipe 52 by a pump to be supplied through the slit 53 between the pairs of rollers 46 a and 46 b, 47 a and 47 b so as to clean the electrophotographic material 180. The cleaned material 180 is dried by the air discharged from the air supply boxes 48 and 49.

The electrophotographic liquid developing apparatus so constructed as shown in FIG. 4 has the following advantages. The developing and cleaning liquids are adhered onto the surface of the electrophotographic material to be taken out therewith. Since the amount of liquid is restricted to a minimum, liquid is less wasted and doesnt reduce the supply thereof. The developing liquid amount brought to the cleaning portion is very small, and accordingly, the cleaning liquid is not as contaminated with the result that the frequency of replacing the cleaning liquid may be reduced. Furthermore, even if the amount of the air discharged from the air supply boxes is lessened relatively, an effective liquid scraping may be possible.

As can be seenfrom the aforementioned description, the apparatus of this invention combines rollers which are not in contact with the image portion of the sheet to be scraped and an air jet to be supplied from a slit provided to cover the rollers thereby effectively scraping the liquid without mechanically destroying the surface of the sheet material.

While the present invention has been described with reference to a few specific embodiments, it is to be understood that these embodiments are only for illustrative purpose and the present invention may have various modifications and changes without departing from the spirit and the scope of the invention as defined by the appended claims.

What is claimed is:

1. An apparatus for removing excess liquid from sheet material comprising:

a pair of flanged rollers mounted for rotation in parallel, spaced relationship, at least one of said rollers being adapted to releasably engage the edges of the sheet material;

means for rotating at least the one of said flanged rollers which is adapted to releasably engage the edges of the sheet material, whereby the sheet ma terial is drawn between said rollers without making contact with the surfaces of either between their flanges;

an air supply box mounted adjacent to one of said rollers and having two lips between which air may be supplied, one of said lips being positioned to prevent the escape of substantially all air between said lip and said roller, and the other of said lips being positioned in spaced relationship to the sheet material and adapted to direct a jet of air against the sheet material and between the rollers, whereby excess liquid is removed from the surface of the sheet material.

2. An apparatus as claimed in claim 1 wherein the first-mentioned of said lips almost contacts said roller but does not prevent its rotation.

3. An apparatus as claimed in claim 1 wherein the first-mentioned of said lips is flexibly mounted and is adapted to contact the surface of said drive roller when air is being supplied to said air supply box, but not to contact said surface when air is not being supplied to leasably engage the edges of the sheet material. 

1. An apparatus for removing excess liquid from sheet material comprising: a pair of flanged rollers mounted for rotation in parallel, spaced relationship, at least one of said rollers being adapted to releasably engage the edges of the sheet material; means for rotating at least the one of said flanged rollers which is adapted to releasably engage the edges of the sheet material, whereby the sheet material is drawn between said rollers without making contact with the surfaces of either between their flanges; an air supply box mounted adjacent to one of said rollers and having two lips between which air may be supplied, one of said lips being positioned to prevent the escape of substantially all air between said lip and said roller, and the other of said lips being positioned in spaced relationship to the sheet material and adapted to direct a jet of air against the sheet material and between the rollers, whereby excess liquid is removed from the surface of the sheet material.
 2. An apparatus as claimed in claim 1 wherein the first-mentioned of said lips almost contacts said roller but does not prevent its rotation.
 3. An apparatus as claimed in claim 1 wherein the first-mentioned of said lips is flexibly mounted and is adapted to contact the surface of said drive roller when air is being supplied to said air supply box, but not to contact said surface when air is not being supplied to said box.
 4. An apparatus as claimed in claim 1 wherein both of said rollers are adapted to releasably engage the edges of the sheet material.
 5. An apparatus as claimed in claim 1 and additionally comprising a second pair of rollers and an endless belt which engages one of said second pair of rollers and which is driven by said means for rotating at least the one of said flanged rollers which is adapted to releasably engage the edges of the sheet material. 